[mlpack] mlpack 2.2.4 released

[Ryan Curtin]

Hello there,

Today I tagged mlpack-2.2.4 and released it.  You can download it here:

  http://www.mlpack.org/files/mlpack-2.2.4.tar.gz

It's a pretty simple bugfix release, precipitated by the finding of a
simple bug in the CF code.  Here's the (short) changelog:

 * Speed and memory improvements for DBSCAN. --single_mode can now be
   used for situations where previously RAM usage was too high.

 * Fix bug in CF causing incorrect recommendations.

I have also been improving the Doxygen documentation!  Take a look:

  http://mlpack.org/docs/mlpack-2.2.4/doxygen/

It's not perfect yet, but I think it is a huge improvement over what was
there before and it's far more navigable.  I am sure there are still
little CSS bits and quirks to be handled, but those will surely be
worked out as time goes on.

Thanks to everyone who has contributed!  The 3.0.0 release is coming at
some point in the future and I think we can all be very excited about
what is in store for that (but, there is still a lot to do before
then---including merging all of our great GSoC projects!).

If you have any issues, as always, feel free to open an issue on Github,
or use the #mlpack IRC channel on freenode to have a discussion!

-- 
Ryan Curtin    | "You know, I think he's got a point."
ryan at ratml.org |   - The Mayor